The Maltsev product of varieties and of a type is a class that consists of all algebras of the type , which have a congruence such that the quotient belongs to and each congruence class of which is a subalgebra of belongs to . The class is closed under subalgebras, direct products, and isomorphic images. However it may not be closed under homomorphic images, and so it may not be a variety. I will present a new sufficient condition for to be a variety and I will discuss various cases in which this sufficient condition is satisfied.
Sufficient conditions for a Maltsev product of two varieties to be a variety